CN110678777A

CN110678777A - LIDAR system

Info

Publication number: CN110678777A
Application number: CN201780087222.3A
Authority: CN
Inventors: 虞爱华; 华一敏
Original assignee: Ona Information Technology (shenzhen) Co Ltd
Current assignee: Ona Information Technology (shenzhen) Co Ltd
Priority date: 2017-05-17
Filing date: 2017-05-17
Publication date: 2020-01-10
Anticipated expiration: 2037-05-17
Also published as: AU2017414401B2; CA3059801A1; CA3059801C; EP3625586A4; US10852398B2; WO2018209606A1; US20200341124A1; EP3625586A1; CN110678777B; EP3625586B1; AU2017414401A1

Abstract

The invention aims to provide a mobile system which comprises a movable platform. The movable platform includes a motorized drive for driving the movable platform into position and a compartment disposed within the movable platform having a housing protected from the ambient environment. The mobile system further includes a LIDAR system mounted on the movable platform, the LIDAR system including a detection fiber laser module for generating and scanning a pulsed detection laser to an external surrounding area, and then reflecting the pulsed detection laser off one or more objects in the surrounding area and detected by the detection fiber laser module to optically sense one or more objects in the surrounding environment. The detection fiber laser module includes a base laser module located within the compartment housing and a plurality of remote laser modules disposed on the movable platform that scan the pulsed detection laser to the surrounding area to optically sense objects in the surrounding area.

Description

LIDAR system

Technical Field

The present invention relates to a LIDAR (light detection and ranging) system, and more particularly, to a LIDAR system, apparatus and technique applied to a movable platform or a motor vehicle based on a technology of sensing surrounding objects.

Background

Object sensing based on light detection and ranging (LIDAR) systems may be used for a variety of applications, including assisting movable platforms or motor vehicles in sensing surrounding objects to avoid collisions. For example, LIDAR may be used as part of an object sensing system for an autonomous vehicle or as a driving assistance system for a human-driven vehicle.

LIDAR systems of the prior art are mostly applied on movable platforms. The movable platform includes a motorized drive that moves the movable platform in place, and a compartment located in an interior portion of the movable platform and configured with an enclosure that provides separation and protection. A light detection and ranging (LIDAR) system mounted on a movable platform includes a detection fiber laser module on the movable platform configured to generate a pulsed detection laser and scan the pulsed detection laser into a surrounding area and to optically sense reflected detection laser light from one or more objects in the surrounding area to determine a specific location of the one or more objects in the surrounding area. Wherein the detection fiber laser module comprises a base laser module located within the compartment housing and a remote laser module of the distribution platform instrument holding portion to scan a pulsed detection laser to the surrounding area for optically sensing the presence of one or more objects in the surrounding area.

The above disclosed techniques are described in more detail in the accompanying drawings, the description and the claims.

Disclosure of Invention

The invention provides an LDIAR system, which comprises a detection laser module arranged on a movable platform. The detection laser module is used for emitting pulse detection laser and scanning the pulse detection laser to an external surrounding area, and detecting the position of one or more objects in the surrounding area and some related information (such as position, size, whether in a motion state and the like) according to the pulse detection laser reflected by one or more objects in the surrounding area. The detection laser module can be configured such that different modules are disposed at different locations on the movable platform. Accordingly, the resources of the detection laser module of the LIDAR system may be distributed over different locations on the movable platform, thereby providing a suitable operating environment for maintaining and operating partitioned resources and improving the overall operational performance of the LIDAR system.

Based on the disclosed techniques, the detection laser modules of the LIDAR system may be divided into a base laser module located within a housing and remote laser modules distributed at certain locations of the movable platform. Thus, the remote laser module is able to scan the pulsed detection laser to the external surrounding area, thereby optically sensing objects in the surrounding area to avoid them interfering with the motion of the movable platform, avoiding accidental collisions between these objects and the movable platform. In particular, in some embodiments, the movable platform may comprise: a motorized drive for moving the movable platform in place, and a compartment located in an interior portion of the movable platform and configured with an enclosure that provides isolation and protects it from the surrounding environment. The base laser module requires a more stable environment, while the remote laser module can be located in a better position, away from the indoor part, in order to transmit probe light to the surroundings of the movable platform for lidar sensing and receiving returned light reflected from the surrounding transmitted probe light.

The movable platform includes a motorized drive system that drives the movable platform to move into position. In one embodiment, the movable platform includes motor vehicles, such as motor boats, and variously configured automobiles, such as cars, vans, trucks, or SUVs, among others. Any vehicle may be included as long as it is suitable for implementing the disclosed on-board LIDAR system. For example, a gasoline stove or a diesel engine as part of the motorized drive, an electric engine as part of the motorized drive, a fuel cell powered engine as part of the motorized drive, a natural gas powered engine as part of the motorized drive, or the like may be part of the motorized drive system. In some embodiments, the movable platform may be an automobile with a hybrid drive system having two different types of engines as part of a motorized drive system.

The invention has the following beneficial effects:

Brief description of the drawings

Fig. 1A and 1B show a car with a driver assistance system or an autonomous driving assistance system provided with an on-board LIDAR system by using a fiber-optic laser source;

2A, 2B, and 2C illustrate embodiments of placing a base laser module of the present invention and a plurality of remote laser modules of an onboard LIDAR system in a vehicle;

fig. 3 illustrates an embodiment of a base laser module and a plurality of remote laser modules of an onboard LIDAR system with remote optical auxiliary amplifiers in the remote laser modules for generating high power output probing laser pulses while minimizing pulse degradation by fiber dispersion and fiber nonlinearity when the base laser module is connected;

fig. 4 illustrates an embodiment of a base laser module and a remote laser module of an onboard LIDAR system, including a seed laser and a downstream optical powered amplifier in the base laser module to maximize shared laser resources;

5A, 5B, 5C, 6,7,8, and 9 illustrate embodiments of a base laser module and a remote laser module in the LIDAR system of FIGS. 3 and 4;

fig. 9A, 9B and 9C illustrate different embodiments of implementing an optical preamplifier in the basic laser module for the LIDAR system of the present invention.

Detailed Description

Preferred embodiment 1:

fig. 3 illustrates an embodiment of a component or device for selectively partitioning such a LIDAR system among a base laser module 12 and a plurality of remote laser modules. In this embodiment, the seed laser diode and seed laser drive electronics for generating the seed detection laser pulses are placed in the base laser module 12 located in the vehicle interior, for example, in a location within the cockpit. The base laser module 12 in this embodiment also includes electrical interface components or means for operating the seed laser diode, a pre-optical amplifier module with an optical gain medium (e.g., doped fiber gain section 94) for optically amplifying the light of the seed laser 31, one or more pump laser diodes to generate the required pump light at a wavelength (e.g., 980nm) of the pump laser 32 that is shorter than the seed detection laser wavelength (e.g., 1550nm) to optically pump the optical gain medium and associated pump laser electronics. The pre-optical amplification module is designed to maintain the amplified seed detection laser pulses at a sufficiently high level to transmit them to a plurality of the remote laser modules over a plurality of LIDAR fiber links, but at a pulse peak power level sufficiently low to avoid the effects of nonlinear optical effects that cause unintended pulse distortion. In order to obtain the required high optical pulse power at the output of each of said remote laser modules, a remote optical auxiliary amplifier is included in each of said remote laser modules. The remote optical auxiliary amplifier is configured to amplify the received seed detection laser pulses scanned by the corresponding remote laser module in a target sensing region external to the vehicle. The design of the remote optical auxiliary amplifier in the remote laser module is based on the consideration that the remote laser module is located at the output of the LLDAR system, so that the high peak power optical probe light pulses generated by the remote laser module are no longer affected by additional fiber dispersion or fiber nonlinear optical effects, while the design avoids pulse distortion caused by spatial fiber dispersion profile management dispersion in the fiber. Based on this design, the fiber used in the fiber laser system can be a relatively low dispersion fiber to reduce dispersion-induced laser pulse distortion, and since the laser pulse peak power is kept low before the output of the remote laser module, the laser pulse distortion induced by fiber nonlinearity can also be kept at an acceptably low level.

In addition to placing the remote optical auxiliary amplifier in the remote laser module, fig. 3 further discloses a preferred solution, where both the power amplifier pump laser module and the electronic driver of the pump laser 32 are placed in the base laser module 12 in order to protect them from extreme vehicle external conditions. With this design, the pump light for the remote optical auxiliary amplifier is generated in the base laser module 12, and therefore the remote optical auxiliary laser in the remote laser module contains an optical combiner for coupling the pump light into the optical gain medium, and no additional electronics or power supply is used. Thus, in this embodiment, all of the seed lasers 31 and the pump lasers 32 and their electronic drivers are located in the base laser module 12 to protect them from extreme external vehicle conditions. This design is advantageous in providing more stable laser operating conditions for the seed laser and the pump laser to improve stability and reliability of the LIDAR system in generating the high power probing laser pulses while reducing instances of optical distortion of the output high power probing laser pulses.

Preferred examples 2,

Fig. 1A shows an embodiment of an automobile with a driver assistance system 131 or an automobile with an autopilot system comprising a LIDAR system as part of its overall sensing system. The LIDAR system optically senses the surrounding environment using outward scanning of probe light. The illustrated LIDAR system includes a base laser module 12 located inside the automobile. The base laser module 12 includes the sensing element of the LIDAR system and is housed within the housing so as not to be exposed to the exterior of the automobile. The base laser module 12 generates detection laser light for LIDAR sensing operations. Different remote laser modules are optically coupled to the base laser module 12 to receive the pulsed detection laser generated by the base laser module 12, while the different remote laser modules are distributed at appropriate locations of the movable platform to scan the pulsed detection laser to a surrounding area outside the vehicle to optically sense different detection beams of different segments or directions in the surrounding area. Each of the remote laser modules also functions as an optical receiver for receiving an optical reflection of its corresponding output scanning probe light, thereby detecting the presence of an object in its optical path of output scanning probe light. Thus, each of the remote laser modules is a remote LIDAR transceiver 11. Fig. 1A shows three different remote LIDAR transceivers: a front remote LIDAR transceiver disposed at a front of the automobile for performing LIDAR sensing in front of the automobile; a rear remote LIDAR transceiver disposed at the rear of the vehicle for LIDAR sensing at the rear of the vehicle; and a top remote LIDAR transceiver disposed on the top of the automobile for performing LIDAR sensing in other directions that may not be covered by the front remote LIDAR transceiver and the rear remote LIDAR transceiver.

In some embodiments of the driver assistance system 131 or the autopilot system 132, the LIDAR system shown in fig. 1 that forms part of the overall automotive sensing system further includes other sensors. Such other sensors may provide additional sensing functionality in the event that the LIDAR system fails to provide adequate sensing due to environmental conditions (e.g., heavy rain, snow or fog) or LIDAR malfunction, avoiding the occurrence of an undersensing condition.

FIG. 1B shows an example of other sensors that may be installed on an automobile as part of an overall sensing system and other additional sensors. In this embodiment, the automobile also has a wireless communication function for wirelessly communicating with other resources to obtain information for driver assistance operation or automatic driving operation. For example, a car may wirelessly communicate with another car in the surrounding area to obtain data onboard the vehicle, or a car wirelessly communicates with a cloud server, the driver assistance system 131 or the autopilot system 132 in the car receives data and information from other sensors 145 onboard the LIDAR system and executes complex algorithms to generate information for driver assistance or autopilot operations.

Fig. 2A also illustrates an example for partitioning various resources in the in-vehicle LIDAR system 141 based on various considerations of the techniques of the present invention. The base laser module 12 contains a plurality of electronics that receive power from a power supply to provide one or more seed diode laser power to generate detection laser light that is modulated based on control signals for LIDAR operation. The generated detection laser is split into different detection laser beams at different output ports of the base laser module 12 and then distributed to different remote laser modules. A LIDAR fiber optic link is used to optically couple a plurality of the remote laser modules to the base laser module 12 and to transmit probe laser pulses from the base laser module 12 to the remote laser modules at preset locations on a vehicle such as shown in fig. 1A. A plurality of the remote laser modules also receive the optically reflected light of the output probe light from the surrounding environment as LIDAR signals that are processed by LIDAR signal processing module 21 to generate LIDAR output signals for driver assistance system 131 or autonomous driving system 132.

Fig. 2B and 2C show two specific embodiments for placing the base laser module 12 and the plurality of remote laser modules based on fig. 2A. In both embodiments, the base laser module 12 is placed in the cockpit-passenger cabin such that the base laser module 12 is well protected from external environmental conditions while each of the remote laser modules is placed at a selected location outside the vehicle to scan the scanning light to a predetermined area around the vehicle.

One of the key requirements of the LIDAR system is that the laser pulses in the probing laser have a relatively high optical power to provide efficient LIDAR sensing under various driving conditions. For example, in some embodiments, the average optical power of the output detection laser beam from each of the remote laser modules may be in the range of about 100 to 1000 milliwatts. Diode lasers for fiber optic communication can be used in the LIRDAR system to generate probing lasers, since they are well-sized, have a certain reliability and durability, and are reasonably priced. The high output optical power requirements of the LIDAR system may be achieved by using the seed laser diode to generate a seed detection laser (e.g., 1550nm wavelength) and then optically amplifying to amplify the optical power of the seed detection laser to achieve the desired high optical power level. The optical amplification process can be performed by either or both of the base laser module 12 and one of the remote laser modules. However, when propagating in an optical fiber link, a high-power laser pulse will inevitably be affected by fiber dispersion and nonlinear optical effects caused in the optical fiber link, and such a high-power laser pulse may be distorted due to the fiber dispersion and nonlinear optical effects. Therefore, the optical amplification process should be carefully designed in the base laser module and the remote laser module to avoid nonlinear optical effects of high power laser pulses in the pass-through fiber and reduce distortion. Optical dispersion compensation can be implemented in the LIDAR system, if necessary, to mitigate fiber-induced optical pulse distortion in the probe laser pulses caused by fiber nonlinearities. Based on this design, the distortion of the optical pulse caused by the fiber nonlinearity depends on the electric field strength of the optical pulse, and becomes apparent as the pulse peak power increases. In addition to pulse peak power, optical pulse distortion also depends on fiber dispersion characteristics in the fiber, where different spectral components propagate at different velocities, causing different time delays in a particular fiber segment to be stretched or compressed. The pulse width depends on whether the fiber segment exhibits positive or negative dispersion. Thus, in designing fiber laser systems to reduce unintended pulse distortion, the fiber can be designed or selected with appropriate dispersion to counteract pulse distortion caused by fiber nonlinear optical effects. For example, one alternative design normal and anomalous dispersion characteristics and spatial distribution of fiber lasers. Based on this interaction between optical nonlinearity and fiber dispersion between optical pulse distortion and pulse width, selecting an appropriate fiber dispersion curve for a given pulse peak power and pulse width can minimize pulse distortion. As part of the disclosed fiber laser design of the LIDAR, different fiber laser design strategies are disclosed to generate the required high power output laser pulses for probe light in LIDAR sensing. Thus, in some fiber laser designs for LIDAR sensing, the optical amplification is spatially distributed to maintain low pulse peak power throughout the fiber laser system and to significantly enhance the pulse peak power just before the laser pulse exits the fiber portion of the fiber laser. By designing the spatial fiber dispersion characteristic in a fiber system, pulse distortion is minimized while managing dispersion induced pulse distortion. In other fiber laser designs for LIDAR sensing, the optical amplification process is focused at a given section of the fiber laser system, e.g., at or near the seed laser 31 in the beginning portion of the fiber laser system, with one or more dispersion compensating fiber sections deployed simultaneously at the back section of the fiber laser system to reduce optical pulse distortion in the output laser pulses.

The vehicle is capable of operating under harsh and diverse conditions, and therefore the electronics, optics, or corresponding components in the onboard LIDAR system 141 should be capable of providing reliable LIDAR sensing operation in harsh environments, such as extremely high or low temperatures, in the event of severe vibration or severe impact. Preferably, as shown in fig. 1A, 2B and 2C, the base laser module 12 of the LIDAR system may be located within a selected interior housing 201, such as the driver-passenger compartment, so as to be isolated from the vehicle surroundings and protected from exposure to the surroundings. The base laser module 12 contains the electronics and the seed laser diode, while a plurality of the remote laser modules, which must be located at vehicle exterior locations 202, may be designed to contain components or devices that are less sensitive to extreme temperature changes.

Fig. 3 shows an alternative arrangement for the base laser module 12 and the remote laser module in such a LIDAR system. In the present embodiment, the seed laser diode and the seed laser drive electronics for generating seed detection laser pulses are disposed in the base laser module 12 located in the vehicle interior, for example, at a location within the driver-passenger cabin. The base laser module 12 in this embodiment also includes electronic interface components or means for controlling the seed laser diode, a pre-optical amplifier module with an optical gain medium (e.g., doped fiber gain section 94) for optically amplifying the light of the seed laser 31, one or more of the pump laser diodes to generate the required pump light at a wavelength (e.g., 980nm) of the pump laser 32 that is shorter than the seed detection laser wavelength (e.g., 1550nm) to optically pump the optical gain medium and associated pump laser 32. This pre-optical amplification module is carefully designed to keep the amplified seed probe laser pulses at a sufficiently high level to transmit laser pulses to a plurality of the remote laser modules over a plurality of the LIDAR fiber links, but at a pulse peak power level sufficiently low to avoid significant nonlinear optical effects that cause unintended pulse distortion. In order to obtain the required high optical pulse power at the output of each of said remote laser modules, a remote optical auxiliary amplifier is included in each of said remote laser modules. The remote optical auxiliary amplifier is configured to amplify the received seed detection laser pulses scanned by the remote laser module in a target sensing region external to the vehicle. The design of the remote optical auxiliary amplifier in the remote laser module is based on the consideration that the remote laser module is located at the output of the LLDAR system, so that the high peak power optical probe light pulses generated by the remote laser module are no longer affected by additional fiber dispersion or fiber nonlinear optical effects, while the design avoids pulse distortion caused by spatial fiber dispersion profile management dispersion in the fiber. Based on this design, the fiber used in the fiber laser system can be a relatively low dispersion fiber to reduce dispersion-induced laser pulse distortion, and since the laser pulse peak power is kept low before the output of the remote laser module, the laser pulse distortion induced by fiber nonlinearity can also be kept at an acceptably low level.

In addition to placing the remote optical auxiliary amplifier in the remote laser module, fig. 3 further discloses a preferred solution, where the booster pump laser 32 module power amplifier pump laser module and the electronic driver of the booster pump laser 32 module power amplifier pump laser module are both placed in the base laser module 12 in order to protect them from extreme vehicle external conditions. With this design, the pump light for the remote optical auxiliary amplifier is generated in the base laser module 12, and therefore the remote optical auxiliary laser in the remote laser module contains an optical combiner for coupling the pump light into the optical gain medium, and no additional electronics or power supply is used. Thus, in this embodiment, all of the seed lasers and the pump lasers and their electronic drivers are located in the base laser module 12 to protect them from extreme external vehicle conditions. This design is advantageous in providing more stable laser operating conditions for the seed laser and the pump laser to improve stability and reliability of the LIDAR system in generating the high power probing laser pulses while reducing instances of optical distortion of the output high power probing laser pulses.

In the embodiment disclosed in fig. 3, each of the remote laser modules comprises an amplifier gain enhancement medium, a pump seed optical combiner and two fiber links for directing the separately generated seed probe laser beam and booster pump laser 32 beam power amplifier pumping from the base laser module 12 to the remote laser modules. A different embodiment is shown in fig. 4. The base laser module 12 includes not only the seed laser and the pump laser and their electronic drivers, but also the optical gain medium for an optical gain amplifier that is capable of producing sufficient optical pass gain to produce high optical power for outputting the probing laser. When the remote laser modules do not contain an optical amplification gain medium, a plurality of the remote laser modules will be pulsed. Fig. 4 concentrates all laser generation and amplification processes in the base laser module 12 to reduce the cost of optical amplification. In a plurality of the LIDAR fiber links between the base laser module 12 and a plurality of the remote laser modules, a dispersion compensating fiber segment is provided to substantially compensate for laser pulse distortion caused by fiber nonlinearity. In the design of fig. 3, the probing laser pulses are amplified to the final required high peak power at each of the remote laser modules to reduce optical distortion caused by fiber nonlinearities, unlike the design of fig. 3, in fig. 4, high peak probing laser pulses are first generated in the base laser module 12 and then distributed to a plurality of the remote laser modules via optical fibers. Thus, as shown in fig. 4, the optical power level output by the base laser module 12 is limited due to the non-linearity of the optical fibers in the plurality of LIDAR fiber links between the base laser module 12 and the plurality of remote laser modules.

Thus, the different designs of fig. 3 and 4 are based on different trade-offs in the LIDAR sensing operation. The design in fig. 3 may be used to provide higher output probing laser pulse power to improve the signal-to-noise ratio of the LIDAR sensing performance. The design in fig. 4 may be used to reduce the overall cost of the LIDAR system. Fig. 3 and 4 use a single seed laser 31 module to generate seed laser light shared by different ones of the remote laser modules. This reduces the costs associated with seed lasers 31 in LIDAR systems. In both designs, each of the remote laser modules includes an optical scanner that scans output detection laser light to sense the surroundings of the vehicle at a corresponding scanning area (e.g., a front end or a rear end of the vehicle) of the remote laser module.

Specific embodiments based on the designs in fig. 3 and 4 are described below.

Fig. 5A shows an embodiment of a fiber laser system implementing the LIDAR system of the design in fig. 1. As shown in fig. 5A, the fiber laser system is provided with an optical enhancement amplifier in the remote laser module, while the seed laser and the pump laser and corresponding laser driving electronics are provided in the base laser module 12. In particular, the base laser module 12 includes a seed detection laser module that includes a seed laser diode to produce the pulsed seed detection laser at a detection laser wavelength (e.g., a seed detection laser wavelength of 1550 nm). The power amplifier pump laser module as a multimode pump laser 33 generates power amplifier pump laser shorter than the detection laser wavelength at the power amplifier pump laser wavelength (for example, 980nm wavelength). The basic laser module 12 includes a basic laser module driving circuit and further includes the seed laser 31. The seed laser 31 is used to power the seed detection laser module and control the seed detection laser module to generate the pulsed seed detection laser. The basic laser module 12 also includes different power amplifier pump drivers. The power amplifier pump driver provides power to the power amplifier pump laser module 32, thereby generating power amplifier pump laser. The fundamental laser module 12 includes a plurality of fundamental laser output ports for respectively carrying different fundamental laser outputs, each of which includes a pair of fundamental seed detection laser outputs and a power amplifier pump laser output. The basic seed detection laser output is that the seed detection laser module generates the pulse seed detection laser with the detection laser wavelength, and the power amplifier pumping laser output is that the power amplifier pumping laser module 32 generates the power amplifier pumping laser with the power amplifier pumping laser wavelength.

As shown in fig. 5A, a plurality of detection fiber links between the base laser module 12 and a plurality of the remote laser modules are coupled to a plurality of the base laser output ports, the plurality of detection fiber links respectively receiving the base laser output for detection of laser wavelength output, such that each detection fiber link is coupled to carry a corresponding base laser output from the base laser output port of the base laser module. The LIDAR system further comprises a plurality of pump fiber links coupled to the fundamental laser output port, the plurality of pump fiber links receiving the power amplifier pump laser 32 output at the power amplifier pump laser wavelength, respectively, such that each of the pump fiber links is coupled to carry the power amplifier pump laser 32 output from the plurality of the fundamental laser output ports of the fundamental laser module 12.

As shown in fig. 5A, the remote laser modules are physically separated from the plurality of base laser modules 12 and the plurality of remote laser modules are located at different locations on the vehicle from one another as shown in fig. 1A, 2B and 2C. Each of the remote laser modules is coupled to one probe fiber link and one pump fiber link to receive a pair of a base seed laser output and an booster pump laser output from a corresponding base laser output port of the base laser module 12. The different remote laser modules are respectively coupled to different ones of the base laser output ports of the base laser module 12. Each of the remote laser modules includes a remote auxiliary optical amplifier to receive and optically amplify the received base probe laser output by the received power amplifier pumped laser output. Since the pump lasers 32 are located in the base laser modules 12, each of the remote laser modules does not have any electronics associated with the pump lasers 32 and optical amplifiers, and therefore can generate an output detection laser beam of amplified detection laser pulses without electrical power.

As shown in fig. 5A, each remote auxiliary optical amplifier in the remote laser module includes a gain portion of a doped double-clad fiber 35 to guide the reception of the power amplifier pump laser 32 output and the basic laser module 12 from the corresponding basic laser output port receives the basic seed detection laser output, and converts the received energy output from the reception power amplifier pump laser 32 of the booster pump laser 32 wavelength power amplifier pump into the laser energy of the detection laser wavelength, and generates the output detection laser beam of the amplified detection laser pulse of the booster pump laser 32 wavelength power amplifier pump. In addition, each of the remote laser modules includes a fiber coupler, and the optical front coupler couples the received output of the power amplifier pump laser 32 and the received output of the fundamental seed detection laser to the gain section of the doped double-clad fiber 35.

Fig. 5A further illustrates an example of the seed laser 31, which seed laser 31 may in some embodiments be a laser diode operating at 1550nm, the average output optical power of which is in the range of 1 to 10 microns. The optical preamplifier is placed in the base laser module 12 by using a preamplifier pump laser 32 (e.g., at 980nm wavelength) to amplify the seed probe laser pulses from the seed laser 31 to a higher power level. A splitter 36 may be provided in the base laser module 12 to split the output of the optical preamplifier into a plurality of seed detection laser beams. A plurality of the seed detection laser beams are directed (e.g., by optical fibers) as the base seed detection laser output to the base laser output port. The basic seed detection laser output is paired with the corresponding power amplifier pump laser 32 output from the power amplifier pump laser 32 module in the basic laser module 12. The peak optical power of each output laser pulse at each of the remote laser modules may be at a very high level, for example, on the order of kilowatts, based on the optical amplification of each of the remote laser modules. Therefore, such high power laser pulses are sent directly out for detection sensing of the LIDAR system in air, and are no longer affected by fiber nonlinearity or dispersion.

Fig. 5A shows all the electronics in the base laser module 12 for laser generation and light amplification. Alternatively, in some embodiments, the pump laser electronics may also be placed in a plurality of the remote laser modules. This design does not require the separation of a separate fiber link that detects the laser at the probing laser wavelength (e.g., 1550nm) in the design of fig. 2 from the pump laser 32 at the shorter pump laser 32 wavelength (e.g., 980nm) in the alternative LIDAR laser design embodiment shown in fig. 5A, 5B. The optical pre-amplifier and its drive electronics in fig. 5B are part of the fundamental laser module 12.

In the optical preamplifier and the optical gain amplifier of fig. 5A and 5B and other designs of the invention, an optical pump may be coupled into the optical gain medium, for example, as shown in fig. 5C, to the gain section of doped fiber 94 in two different embodiments. In the embodiment described in the upper part of fig. 5C, the seed detection laser and the multimode pump laser are combined into a fiber gain section (e.g., a double-clad gain fiber section) with the same optical propagation direction using a multimode fiber coupler. Another embodiment is shown in the lower part of fig. 5C, where a multimode fiber coupler is used to guide the multimode pump laser 32 laser to a fiber gain section (e.g., a double-clad gain fiber section) that propagates in the opposite direction to the optical propagation direction of the seed probe laser, thereby providing high pump laser efficiency resulting in better optical separation between the amplified probe laser and the pump laser 32 laser. In fig. 5C the multi-pump laser is able to increase the total pump power level for amplification operation.

Fig. 6 shows an embodiment of the design in fig. 4. In this embodiment, the seed laser 31, the pump laser 32 for optical pre-amplification, the optical power amplifier pump laser, and the driver electronics of the optical power amplifier pump laser are all housed in the basic laser module 12. Specifically, based on one of the two designs in fig. 5C, a multimode pump combiner 34 is placed downstream of the optical preamplifier to combine the multiple booster pump lasers 32 beam power amplifier pumps into the fiber gain section of the optical booster amplifier. In this embodiment a plurality of multimode pump sources may be provided. As shown, the multimode pump combiner 34 combines the beam of the booster pump laser 32 and the seed detection laser output by the optical preamplifier so that both co-propagate in the gain section of the fiber. In a fiber link that carries a plurality of amplified detection laser beams from different ones of the base output ports to different ones of the remote laser modules, a dispersion compensating fiber segment is provided to mitigate fiber dispersion and pulse distortion. Sharing the seed laser 31, the optical amplifier, pump laser, and associated driver electronics in the base laser module 12 among different remote laser modules with remote laser scanners can provide significant cost savings for the LIDAR system.

Fig. 7 shows another embodiment of the design in fig. 4. Wherein, different optical pump lasers and different optical power amplifiers are respectively placed in the basic laser module 12 to serve different remote laser modules. In this embodiment, the detection laser from the optical preamplifier is first split into a plurality of detection laser beams, and the split pump laser and the plurality of optical booster amplifiers couple and amplify the plurality of detection laser beams to cause the plurality of detection laser beams to produce outputs at different base output ports. Specifically, the basic laser module 12 includes a seed detection laser module for generating a pulse seed detection laser at a detection laser wavelength, a splitter 36 for splitting the pulse seed detection laser from the seed detection laser module into different seed detection laser beams, different power amplifier pump lasers generated at a power amplifier pump laser wavelength, and an optical combiner coupled to receive the different seed detection laser beams and the different power amplifier pump laser beams, respectively. Each optical combiner combines the received booster pump laser 32 laser beam power amplifier pumping and the received seed detection laser beam into a combined beam. The fundamental laser module 12 includes a plurality of auxiliary optical amplifiers coupled to different ones of the optical combiners such that each auxiliary optical amplifier receives an output probing laser beam optically energized by a power amplifier pump laser 32 to amplify the pulsed seed probing laser to produce amplified probing laser pulses. Such amplified detection laser beams are output from corresponding different said base laser output ports of said base laser module 12. Each of the detection fiber links is coupled to a base laser output port to receive a different detection laser output of a detection laser wavelength, respectively, such that each of the detection fiber links is coupled to transmit the detection laser output to a corresponding remote laser module, the remote laser module including an optical scanner. The optical scanner scans the received detection laser output as a scanned output detection laser beam for LIDAR sensing. The shared laser resource in fig. 7 is smaller than the shared laser resource in fig. 6. And different detection laser output power levels can be more flexibly controlled at different basic laser output ports according to different power level requirements.

As with the embodiment shown in fig. lA, the remote laser module at the front, which performs LIDAR sensing in front of the vehicle, tends to require a higher laser power level and a longer sensing range than the remote laser module at the rear, since the vehicle is moving faster than it is moving backwards. Thus, the pump laser 32 and the optical booster amplifier for the remote laser module in front can produce a higher optical amplification than the pump laser 32 and the optical booster amplifier for the remote laser module in rear. The implementation of this embodiment is facilitated by the separate pump lasers and optical booster amplifiers of fig. 7.

Fig. 8 shows another embodiment combining the designs in fig. 1 and 2, enabling further cost savings. In particular, by sharing laser resources between a plurality of said remote laser modules at predetermined locations based on the design in fig. 3, and including a remote optical booster amplifier generating a higher power probe beam based on the design in fig. 4, a plurality of said remote laser modules at predetermined locations. FIG. 8 provides various applications in different considerations. For example, the LIDAR system of fig. 8 may use a remote laser module provided with a remote optical intensifier amplifier based on the design of fig. 3, acting as a front remote laser module placed at the front of the vehicle, producing a higher power probe beam. While others of the remote laser modules, placed facing the rear of the vehicle, are used for short-range LIDAR sensing based on the shared design in fig. 4.

In the above-described embodiments, in a laser system used in an in-vehicle LIDAR system 141s, the optical pre-amplifier may be implemented in different configurations based on the needs of a particular system or application. Fig. 9A, 9B and 9C show three embodiments with different optical amplification stages for an optical preamplifier. Fig. 9A shows a single stage optical preamplifier including photodetector monitor PD1(92) and photodetector monitor PD2 (93). The photodetector monitor PD1(92) is used to monitor the received probe laser power from the seed laser 31 before amplification by the optical preamplifier. The photodetector monitor PD2(93) monitors the output detection laser power through an optical preamplifier. Fig. 9B shows a two-stage optical preamplifier including two fiber gain sections in two amplification stages connected in series. An optical pump power branch 95 stage is coupled between the two stages for (1) filtering the amplified probe laser light produced by the first stage and (2) redirecting the unused pump laser 32 through a branch path to the fiber gain medium of the optical pump 91 so that the two stages share a common source of pump laser 32. Fig. 9C shows another embodiment of a two-stage optical preamplifier comprising two fiber gain sections in two amplification stages connected in series for sharing the pump laser 32 in common. In fig. 9B and 9C, the photodetector monitor PD1(92) is provided to monitor the probe laser power received from the seed laser 31 prior to amplification, and the photodetector monitor PD2(93) is provided to monitor the output probe laser power after magnitude amplification.

While this invention includes many specifics, these should not be construed as limitations on the scope of the invention as claimed, but rather as descriptions of features specific to particular embodiments. Certain features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any combination in a single embodiment. Also, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, although the above features may be described as applied in certain combinations, these features may be separated from the combinations in certain cases and appropriately modified or modified as required, which also fall within the scope of the present invention.

Similarly, while specific operations are depicted in the drawings of the invention in a particular order, this depiction should not be construed as being limited to only those operations being performed in the particular order, and the invention is not limited to sequential operations as long as all illustrated operations achieve desirable results. Additionally, the separation of various system components in the embodiments described in this disclosure should not be understood as requiring such separation in all embodiments.

The content of the above description only describes part of the embodiments of the present invention, and various modifications, equivalents and substitutions based on the present invention should be made within the scope of the present invention.

Claims

1. A mobile system, comprising:

a movable platform including a motorized drive for moving the movable platform into position and a compartment disposed within the movable platform, the compartment having an enclosure protected from the ambient environment;

a LIDAR system mounted on the movable platform, the LIDAR system including a detection fiber laser module for generating and scanning a pulsed detection laser to an external surrounding area and then one or more objects from the surrounding area reflecting the pulsed detection laser and being detected by the detection fiber laser module to optically sense one or more objects in the surrounding environment, wherein the detection fiber laser module includes a base laser module located within a compartment housing and a plurality of remote laser modules distributed on an instrument holder of the movable platform that scan the pulsed detection laser to the surrounding area to optically sense one or more objects in the surrounding area;

wherein the basic laser module comprises: (1) the laser system comprises a seed detection laser module, a power amplifier pumping laser module, a basic laser module driving circuit and a plurality of basic laser output ports, wherein the seed detection laser module is used for generating pulse seed detection laser according to detection laser wavelength, (2) the power amplifier pumping laser module is used for generating power amplifier pumping laser according to power amplifier pumping laser wavelength, (3) the basic laser module driving circuit is used for providing electric energy for the seed detection laser module so as to generate the pulse seed detection laser, and is used for providing electric energy for the power amplifier pumping laser module so as to generate the power amplifier pumping laser, and (4) the basic laser output ports are respectively;

each basic laser output comprises a pair of basic seed detection laser output and power amplifier pumping laser output, the basic seed detection laser output is the pulse seed detection laser generated by the seed detection laser module according to the detection laser wavelength, and the power amplifier pumping laser output is the power amplifier pumping laser generated by the power amplifier pumping laser module according to the power amplifier pumping laser wavelength;

wherein the LIDAR system comprises a plurality of probe fiber links coupled to a plurality of the fundamental laser output ports and a plurality of pump fiber links coupled to a plurality of the fundamental laser output ports, the plurality of probe fiber links respectively receiving fundamental laser output at a probe laser wavelength output such that each probe fiber link is coupled to carry a corresponding the fundamental laser output from the fundamental laser output port of the fundamental laser module and the plurality of pump fiber links respectively receiving the power amplifier pump laser output at a power amplifier pump laser wavelength such that each pump fiber link is coupled to carry the power amplifier pump laser output from the plurality of the fundamental laser output ports of the fundamental laser module;

wherein the plurality of remote laser modules are physically separated from the base laser module and are located at different positions, each remote laser module being coupled to one of the probing fiber links and one of the pumping fiber links to receive a pair of the base seed laser output and the power amplifier pumping laser output from a corresponding base laser output port of the base laser module, different remote laser modules being coupled to different base laser output ports of the base laser module respectively, wherein each of the remote laser modules comprises a remote auxiliary optical amplifier coupled to receive the power amplifier pumped laser output and optically energized by the received power amplifier pumped laser output, thereby generating an amplified output detection laser beam of said detection laser pulses for sensing the surrounding area without the need for electrical energy.

2. Mobile system according to claim 1,

the remote auxiliary optical amplifier in each remote laser module comprises a doped double-clad optical fiber gain part, so that a received power amplifier pumping laser output and a basic seed detection laser output received from a corresponding basic laser output port of the basic laser module are guided, and the energy of the received power amplifier pumping laser output at the power amplifier pumping wavelength is converted into the laser energy at the detection laser wavelength, so that an output detection laser beam of a detection laser pulse amplified at the power amplifier pumping laser wavelength is generated;

each of the remote laser modules includes an optical fiber coupler that couples the received power amplifier pump laser output and the received fundamental seed detection laser output to the doped double-clad fiber gain section.

3. The mobile system of claim 2, wherein the doped double-clad fiber gain section is rare-earth-doped.

4. The mobile system of claim 2, wherein the doped double-clad fiber gain section is erbium doped.

5. The mobile system of claim 1, wherein the seed detection laser module is configured to generate a pulse seed detection laser with a detection wavelength of 1550nm, and the power amplifier pump laser module is configured to generate a power amplifier pump laser with a power amplifier pump laser wavelength of 980 nm.

6. The translation system of claim 1, wherein the fundamental laser module includes a preamplifier coupled to receive and amplify the pulsed seed detection laser at the detection laser wavelength to produce each of the fundamental seed detection laser outputs at a plurality of the fundamental laser output ports.

7. The mobile system of claim 6, wherein the base laser module comprises an optical splitter disposed downstream of the preamplifier, the optical splitter configured to receive the output light from the preamplifier and split the output light into a plurality of the base seed detection laser outputs to the base laser output port.

8. The mobile system of claim 7, wherein the optical splitter is coupled to further receive the power amplifier pump laser from the power amplifier pump laser module and to divide the received power amplifier pump laser into different power amplifier pump laser outputs at the fundamental laser output port, respectively.

9. The mobile system of claim 8, wherein the power amplifier pump laser module is configured to generate the power amplifier pump laser as a multi-mode beam.

10. The mobile system of claim 8, wherein the power amplifier pump laser module comprises different power amplifier pump lasers, and the different power amplifier pump lasers respectively generate different power amplifier pump laser outputs at the fundamental laser output port.

11. The mobile system of claim 1, wherein each of the remote laser modules further comprises an optical scanner configured to receive the output detection laser beam from the detection laser pulses amplified by the remote auxiliary optical amplifier and to treat the output detection laser beam as a scanned output detection laser beam.

12. The mobile system of claim 1, wherein each of the remote laser modules further comprises a light receiver that receives reflected light caused by an object in the path of one of the scanned-out detection laser beams.

13. The mobile system of claim 1, wherein the movable platform is an automobile.

14. The locomotion system of claim 13, wherein the automobile comprises a gasoline or diesel engine as part of the motorized drive.

15. The locomotion system of claim 13, wherein the automobile comprises an electric motor as part of the motorized drive.

16. The locomotion system of claim 13, wherein the automobile comprises a fuel cell-driven engine as part of the motorized drive.

17. The locomotion system of claim 13, wherein the automobile comprises a natural gas-driven engine as part of the motorized drive.

18. The locomotion system of claim 13, wherein the vehicle comprises a hybrid drive system having two different types of engines as part of the motorized drive.

19. The mobile system of claim 13, wherein the compartment is located at a position within or near a vehicle cab.

20. The mobile system of claim 13, wherein one or more of the remote laser modules are mounted to be able to direct and scan the pulsed detection laser to the front of the automobile while one or more of the remote laser modules are mounted to be able to direct and scan the pulsed detection laser to other directions around the automobile.

21. The locomotion system of claim 1, wherein the mobile platform floats on the water surface.

22. A mobile system, comprising:

wherein the basic laser module comprises: (1) a seed detection laser module for generating a pulse seed detection laser with a detection laser wavelength, (2) a power amplifier pump laser module for generating a power amplifier pump laser with a power amplifier pump laser wavelength, (3) an auxiliary optical amplifier for coupling to receive the pulse seed detection laser and the power amplifier pump laser and being optically energized by the power amplifier pump laser to amplify the pulse seed detection laser to generate an amplified output detection laser beam of the output detection laser, and (4) an optical splitter for splitting the detection laser beam of the amplified detection laser pulse into different detection laser outputs; (5) a plurality of fundamental laser output ports for respectively receiving different said detection laser outputs from said beam splitter;

wherein the LIDAR system comprises a plurality of detection fiber links coupled to the base laser output port to respectively receive the different detection laser outputs at a detection laser wavelength, such that each of the detection fiber links is coupled to carry the detection laser outputs; and

wherein, it is a plurality of remote laser module with basic laser module physical separation, and every the position difference that remote laser module is fast, every remote laser module is followed a corresponding basic laser output port coupling of basic laser module is to one survey the optic fibre link, wherein every remote laser module includes the optical scanner, the optical scanner scans and receives a plurality of survey laser output is as scanning output detection laser beam.

23. The mobile system of claim 22, wherein the auxiliary optical amplifier comprises:

the optical coupler is used for receiving the power amplifier pumping laser from the power amplifier pumping laser module and the pulse seed detection laser from the seed detection laser module and combining the power amplifier pumping laser and the pulse seed detection laser into a light beam; and

and the double-clad optical fiber amplifier is used for receiving the combined light beam from the optical coupler so as to amplify the received pulse seed detection laser by using the power amplifier pumping laser.

24. The mobile system of claim 23, wherein the power amplifier pump laser module is configured to generate the power amplifier pump laser as a multimode pump beam to the optical coupler.

25. The mobile system of claim 22, wherein the seed detection laser module comprises:

a seed laser that generates an initial pulse seed detection laser; and

a preamplifier for receiving the initial pulse seed detection laser from the seed laser to amplify the received initial pulse seed detection laser into the pulse seed detection laser received by the auxiliary optical amplifier.

26. The mobile system according to claim 22, wherein each of said probe fiber links comprises a DCF segment that suppresses pulse spreading.

27. A mobile system, comprising:

wherein the basic laser module comprises: (1) the seed detection laser module is used for generating pulse seed detection laser by using detection laser wavelength; (2) a beam splitter that splits the pulsed seed detection laser from the seed detection laser module into different seed detection laser beams; (3) different power amplifier pumping lasers are used for generating power amplifier pumping laser beams at the wavelength of the power amplifier pumping lasers; (4) a plurality of auxiliary optical amplifiers coupled such that each of the auxiliary optical amplifiers receives the corresponding power amplifier pump laser beam and is optically energized by the power amplifier pump laser to amplify the pulse seed detection laser to generate an amplified output detection laser beam of detection laser pulses; (5) a plurality of fundamental laser output ports for respectively receiving different said detection laser outputs from a plurality of said auxiliary optical amplifiers;

wherein the LIDAR system comprises a plurality of probing fiber links coupled to a plurality of the base laser output ports to respectively receive different ones of the probing laser outputs at a probing laser wavelength, such that each of the probing fiber links is coupled to carry one of the probing laser outputs; and

wherein, it is a plurality of remote laser module with basic laser module physical separation, and every the position diverse of remote laser module is fast, every remote laser module is followed corresponding one of basic laser module the basic laser output port couples to one survey the optic fibre link, wherein every remote laser module includes the optical scanner, the optical scanner scans received a plurality of survey laser output is as scanning output detection laser beam.

28. The mobile system of claim 27, wherein the power amplifier pump laser module is configured to generate the power amplifier pump laser as a multimode pump beam.

29. The mobile system of claim 27, wherein the seed detection laser module comprises:

a seed laser that generates an initial pulse seed detection laser; and

a preamplifier for receiving the initial pulse seed detection laser from the seed laser to amplify the received initial pulse seed detection laser into the pulse seed detection laser received by the optical splitter.

30. The mobile system according to claim 27, wherein each of said probe fiber links comprises a DCF segment that suppresses pulse spreading.

31. A mobile system, comprising:

wherein the basic laser module comprises: (1) seed detection laser module for producing pulse seed detection laser with detection laser wavelength, (2) optical splitter will come from seed detection laser module pulse seed detection laser divides into different seed detection laser beams, (3) a plurality of first booster pump laser for produce first booster pump laser beam with booster pump laser wavelength, (4) a plurality of second booster pump laser, be used for producing second booster pump laser beam under the booster pump laser wavelength, (5) a plurality of basic laser module optical combiner, be used for respectively receiving and come from optical splitter output the different seed detection laser beams of the first part of seed detection laser beam, and still the coupling is in order to receive a plurality of first booster pump laser produces first booster pump laser beam, every basic laser module optical combiner is operable with received first booster pump laser beam and received seed detection laser beam combination laser beam A combined beam, (6) a plurality of basic laser module assist optical amplifiers respectively coupled to the basic laser module optical combiners such that each of the basic laser module assist optical amplifiers receives the combined beam from the corresponding basic laser module optical combiner and is optically energized by a booster pump laser to amplify the pulse seed detection laser to produce an amplified detection laser pulse output detection laser beam, (7) a plurality of first basic laser output ports respectively for receiving different output detection laser beams from the basic laser module assist optical amplifiers; (8) a plurality of second base laser output ports for receiving a second portion of the seed detection laser beam output by the optical splitter and a second booster pump laser beam from the second booster pump laser, respectively;

wherein the LIDAR system comprises a plurality of first detection fiber links coupled to a plurality of the first fundamental laser output ports for respectively receiving different ones of the detection laser outputs amplified by a fundamental laser module booster optical amplifier and a plurality of second detection fiber links coupled to a second fundamental laser output port for respectively receiving different ones of the pump laser wavelengths amplified by a fundamental laser module booster optical amplifier, a plurality of the second detection fiber links for respectively receiving different ones of the pump laser beams not enhanced by a fundamental laser module on a second portion of the seed detection laser beams, a plurality of the pump fiber links coupled to the second fundamental laser output port for respectively receiving the second booster pump laser beams such that each of the pump fiber links is coupled to carry the second booster pump laser beams,

wherein the LIDAR system comprises a plurality of first remote laser modules, each of the first remote laser modules being separate from the base laser module and coupled to each of the first detection fiber links, respectively, wherein each of the first remote laser modules comprises an optical scanner that scans the received detection laser output as a first scan output detection laser beam; and

wherein the LIDAR system includes a plurality of second remote laser modules physically separated from the fundamental laser module and coupled to a plurality of the second detection fiber links and a plurality of the pump fiber links, each of the second remote laser modules coupled to one of the second detection fiber links and one of the pump fiber links to receive a pair of seed detection laser beams in a second portion of the seed detection laser beams that are not amplified by the fundamental laser module booster pump amplifier and the second booster pump laser output, wherein each of the second remote laser modules includes: (1) a remote assist optical amplifier coupled to receive the second booster pump laser output and optically energized by the second booster pump laser to amplify the received seed detection laser beam without requiring electrical power to produce a second output detection laser beam of amplified detection laser pulses, and (2) an optical scanner for scanning the second output detection laser beam from the remote assist optical amplifier as a second scanned output detection laser beam.

32. The mobile system according to claim 31, wherein each of said first probe fiber links comprises a DCF segment that suppresses pulse spreading.

33. A mobile system, comprising:

wherein the fundamental laser module comprises (1) a seed detection laser module for generating pulsed seed detection laser at a detection laser wavelength, (2) a fundamental laser module drive circuit for providing electrical energy to the seed detection laser module to generate the pulsed seed detection laser, (3) a plurality of fundamental laser output ports each carrying a plurality of fundamental laser outputs, each of the fundamental laser outputs comprising a fundamental seed detection laser output at a detection laser wavelength from the pulsed seed detection laser emitted by the seed detection laser module;

wherein the LIDAR system comprises a plurality of probing fiber links coupled to the base laser output port to respectively receive different probing laser outputs at a probing laser wavelength, such that each probing fiber link is coupled to carry a probing laser output; and

wherein the plurality of remote laser modules are physically separated from the base laser module, and each remote laser module has a different position, each remote laser module is coupled to one of the detection fiber links from a corresponding base laser output port of the base laser module, different remote laser modules are respectively coupled to different base laser output ports of the base laser module, each remote laser module comprising: (1) power amplifier pumping laser module for produce power amplifier pumping laser under power amplifier pumping laser wavelength, (2) long-range supplementary optical amplifier, long-range supplementary optical amplifier coupling is in order to receive power amplifier pumping laser and by the basis detection laser output of optics circular telegram in order to enlarge the receipt to produce the output detection laser beam of the detection laser pulse after enlargeing, (3) optical scanner for the output detection laser beam of the detection laser pulse after the scanning amplification, (4) long-range laser module drive circuit, the coupling is used for doing power amplifier pumping laser module with optical scanner provides the electric energy.

34. The mobile system of claim 33, wherein the remote auxiliary optical amplifier in each of the remote laser modules comprises a doped double-clad fiber gain section for converting energy of the power amplifier pump laser at the power amplifier pump laser wavelength into laser energy at the probing laser wavelength to generate an amplified output probing laser beam of probing laser pulses at the power amplifier pump laser wavelength.

35. The mobile system of claim 33, wherein each of the remote laser modules comprises a fiber coupler that couples the received power amplifier pump laser and the received fundamental seed detection laser output to a doped double-clad fiber gain section.